The effects of active elements on adhesion strength of SiC/Cu interface in SiC reinforced Cu-based composite: A first-principles investigation

Abstract

Application of SiC reinforced Cu-based composites has been greatly limited by the weak interfacial bonding strength between SiC and Cu matrix. In this work, the active elements (Fe, W, Zr and Ti) were introduced to enhance the adhesion strength of SiC/Cu interface, and the strengthening mechanism was revealed by using the first-principles calculations at the atomic level. The results show that the C-terminated SiC(111)/Cu(111) interface with fcc stacking sequence (C-fcc-Cu) has the largest adhesion strength, which is primarily contributed by the strong hybridizations between interfacial C-p, Si-p and Cu-d orbitals. Interestingly, the addition of those active dopants can significantly improve the work of adhesion and enhance the interfacial bonding strength of C-fcc-Cu interface. More importantly, Zr and Ti atoms are prone to segregate to interface and then combine with interfacial C atoms to form new compounds (ZrC and TiC), which could act as interfacial binders to enhance interfacial atoms interactions. The corresponding strengthening micro-mechanism was determined by the analysis of electronic properties. The Fe, W, Zr and Ti dopants can enhance the electron concentration at interface and improve the electron transfer, orbital hybridizations between dopants and C atoms.